In MA you have to register your business name with the town and that protects you from any one else using it within the county. If you have a corporation, you are protected from any one else using it in the whole state.

Laws vary from state to state, and probably from one county to the next.

__________________
A monk asked Tozan, "How can we escape the cold and heat?" Tozan replied, "Why not go where there is no cold and heat?" "Is there such a place?" the monk asked. Tozan commented, "When cold, be thoroughly cold; when hot, be hot through and through."